The invention is more particularly concerned with intake manifolds comprising, on the one hand, an intake or plenum chamber of elongate shape and provided at one of its longitudinal ends with an intake aperture and, on the other hand, at least two pipes laterally connected to said chamber, said pipes extending at least partially around said intake chamber from their inlet apertures opening therein and having a curved structure over at least a portion of their length.
Until now this type of manifold has generally been produced by joining three distinct parts, namely a first part forming a portion of the wall of the plenum chamber, a second part forming the complementary portion of the plenum chamber and a longitudinal portion of the pipes and a third part forming the longitudinal part complementary to said pipes.
To produce this manifold, it is therefore necessary to provide two joining interfaces and to proceed with two vibration welding operations, resulting in a high manufacturing cost, an increased risk of producing non-specification parts and the use of a greater mass of material.
Furthermore, the multiplication of joining zones, and in particular the presence of joint zones in the region of inlet and outlet apertures for the pipes structurally and mechanically weakens the resultant manifold.